Container

ABSTRACT

A container for receiving a detesting dust article and transporting thereof, which is mounted on a loader disposed in a border portion between a high cleanliness room and a low cleanliness room, including means by the use of which a cover thereof is opened and closed by an opener mechanism to communicate and shut the opening portion thereof and the high cleanliness room.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a container for receiving andtransporting an article such as a substrate necessary to be kept underthe condition of high cleanliness during being transported. There isdescribed hereunder a container in relation to a semiconductor substratesuch as a silicon wafer or a liquid crystal substrate as the abovearticle, in particular a silicon wafer as an example, however, thepresent invention is not limited to the above article. The container ofthe present invention is applicable to any kind of article necessary tobe kept under the condition of high cleanliness during beingtransported.

2. Background of the Invention

The semiconductor substrate, in particular silicon wafer is contaminatedwhen dust or vaporized organic compounds (hereinafter referred to as“dust”) are attached thereto, thus leading to a lower productivity,i.e., the rate of producing products with high-quality is low. It istherefore necessary to maintain high cleanliness in the surroundings ofthe silicon wafer when the silicon wafer is transported. Morespecifically, the silicon wafer is one of the articles necessary to bekept under the condition of high cleanliness during transported(hereinafter referred to as a “detesting dust article”).

In general, the silicon wafer is worked in a room where cleanliness ishigh (hereinafter referred to as a “high cleanliness room”), i.e., socalled a clean room. On the other hand, when the silicon wafer istransported, the silicon wafer is received in an airtightly sealedcontainer, the inside of which is kept under the condition of highcleanliness (hereinafter referred to as a “container”), and then, thecontainer with the silicon wafer received therein is transported. Thus,the silicon wafer can be transported through a room in which the degreeof cleanliness is low or outdoor (hereinafter referred to as a “lowcleanliness room”), avoiding the silicon wafer from being contaminatedby dust or the like during transported.

There is disposed a loader having an opening portion, which openingportion can be closed, in the border portion between the highcleanliness room and the low cleanliness room. The silicon wafer ismoved through the above loader from the inner space of the containerwith high cleanliness to the high cleanliness room, then worked therein(hereinafter referred to as “loading”). In addition, the silicon waferis moved through the loader from the high cleanliness room to the innerspace of the container with high cleanliness, then transferred toanother treatment step (hereinafter referred to as “unloading”).

More specifically, the silicon wafer is loaded or unloaded through theabove opening portion of the loader. The container has a cover (i.e.,lid) in a direction to the opening portion of the loader, which cover isopened when the silicon wafer is loaded or unloaded.

When the silicon wafer is not loaded or unloaded, the opening portion ofthe loader is kept closed so as to prevent dust from floating into thehigh cleanliness room from the low cleanliness room. A door may bedisposed in the opening portion so that the opening portion can beopened or closed by the door.

In this case, the door may be large enough to completely close theopening portion of the loader. In addition, the door may be the size inwhich the door is about 5 mm smaller in each side than the respectiveside of the opening portion of the loader in such manner that there isprovided aperture (open space) between the door and the opening portionof the loader, while the air pressure in the high cleanliness room iskept higher than that in the lower cleanliness room, thus air flowsthrough the aperture from the high cleanliness room to the lowcleanliness room.

The following standards for the above container and loader are proposedand applied: SEMI (Semiconductor Equipment and Material International)Standard E47.1 [Box/Pod (FOUP)], E15.1[Tool Load Port], E57[KinematicCoupling], E62[Front-Opening Interface Standard (FIMS), E63 [Box/Openerto Tool Standard (BOLTS) and the like (hereinafter referred to as“Standard”).

RELATED ART

An example of the conventional container is described in FIG. 1 as forreference.

There is formed an opening portion 103 at the frontal portion of thecontainer 102, which opening portion 103 is opened and closed by a cover105. There is fixed a part named as a teeth 109 on the inner wall of thecontainer, which holds a plurality of silicon wafers 107 in parallel andhorizontally within the container 101.

There is formed key holes 111 on the outer surface of the cover 105, towhich an opener mechanism disposed on the loader is applied. Morespecifically, keys of the opener mechanism are inserted into the keyholes 111 and turned to cause the lock mechanism disposed in the cover105 to operate. As a result, four locking pawls 115 in the lockmechanism, which protrude from four window portions 113 provided in theframe portion of the opening portion 103, move backward in such mannerthat the locking pawls are released from recessed portions 117 providedon the frame portion of the container in the opening portion 103, thusthe locking is disengaged. Then, the cover 105 is removed from the frameportion of the container in the opening portion 103.

However, according to the conventional container, when the lockmechanism comprising gears, cams and the like is operated, dust isgenerated to flow out of the window portions 113 in the frame portion ofthe cover 105. The thus generated dust flows into the inside of thecontainer by the air stream generated at the instant when the lockingpawls 115 are disengaged and the cover 105 is released, thuscontaminating the silicon wafer 107 in the container. More specifically,there is caused to occur the difference in air pressure between the highcleanliness room and the inside of the container 101 by the positivepressure applied to the high cleanliness room at the instant when thecover 105 is released, thus producing the air stream. The dust iscarried by the air stream toward the inside of the container 101 andthen contaminates the inside thereof.

There is described the structure around the hitched portion 117 in moredetail with reference to FIG. 1(B). The frame portion of the container101 in the opening portion 103 protrudes forward so as to form flange119. More specifically, the front end of the flange 119 forms the frontend of the frame portion of the container in the opening portion 103.The recessed portion which is the hitched portion 117 is formed on theinner surface of the flange 119. Accordingly when the lock mechanism isoperated to be engaged, both of the locking pawls 115 and windowsportions 113 are located inward of the front end of the flange 119. Theair stream is separated at the front end of the flange 119 into twostreams comprising an outer stream (lower stream) and an inner stream(upper stream), as shown in FIG. 1(B) by arrows. The inner stream passesalong the inner surface of the flange 119 to carry the dust dischargedfrom the window portions 113 through the space between the frame portionof the cover 105 and the flange 119 to the inside of the container, thuscontaminating the inside of the container 101.

Furthermore, in addition to the dust generated in the lock mechanism,the dust generated by the friction between the locking pawl and thehitched portion 117 also contaminates the inside of the container.

Furthermore, when the inner surface of the flange 119 in the openingportion 103 is scraped by the frame portion of the cover 105, dust isgenerated, thus contaminating the inside of the container 101.

The present invention is proposed to solve the above problems in theconventional container. The purpose of the present invention istherefore to provide a container for receiving and transporting thedetesting dust article which can remarkably reduce the dust generatedwhen the cover of the container is opened and closed, and prevent theinside of the container from being contaminated by the dust.

DISCLOSURE OF THE INVENTION

In order to attain the above object, there is provided a followinginvention.

There is provided a first embodiment of the invention, which is acontainer for receiving and transporting a detesting dust article, whichis mounted on a loader disposed in a border portion between a highcleanliness room and a low cleanliness room, a cover of which is openedand closed by an opener mechanism disposed in said loader in such mannerthat an opening portion of said container and said high cleanliness roomis connected and shut, which includes:

(a) a lock mechanism disposed in said cover and operated by said openermechanism provided in said loader for locking and releasing said cover;

(b) a locking pawl in said lock mechanism for protruding from a frameportion of said cover and catching a hitched portion provided in a frameportion of said container in said opening portion; and

(c) a window portion provided in said frame portion of said cover, fromwhich said locking pawl protrudes, said window portion being disposed soas to be located outward and backward of an front end of said frameportion of said container in said opening portion, when said lockingpawl is hitched to said hitched portion provided in said frame portionof said container in said opening portion.

According to the invention, since the window portion is located outwardand backward from a tip of the opening portion, the dust generatedduring the operation of the lock mechanism and flowed out of the windowportion is carried to the low cleanliness room by the air streamgenerated at the instance when the pawls are disengaged and the cover isreleased, thus preventing the dust from flowing backward through the tipof the opening portion to the inside of the container not to contaminatethe inside of the container.

The second embodiment of the invention is a container, wherein saidframe portion of said container in said opening portion includes aninner flange, an outer flange and said hitched portion which is locatedbetween said inner flange and said outer flange, said window portion forsaid locking pawl is located in said hitched portion when said lockingpawl is hitched to said hitched portion, and said front end of saidframe portion of said container in said opening portion comprises a tipof said inner flange.

According to the invention, since a dead-end space is provided betweenthe inner flange and the outer flange in which space the air stream ishardly generated, it is possible to prevent the dust from flowingbackward through the tip of the opening portion to the inside of thecontainer.

Third embodiment of the invention is a container for receiving andtransporting a detesting dust article, which is mounted on a loaderdisposed in a border portion between a high cleanliness room and a lowcleanliness room, a cover of which is opened and closed by an openermechanism disposed in said loader in such manner that an opening portionof said container and said high cleanliness room is connected and shut,which includes:

(a) a lock mechanism disposed in said cover and operated by said openermechanism provided in said loader for locking and releasing said cover;

(b) a locking pawl in said lock mechanism for protruding from a frameportion of said cover and catching a hitched portion provided in a frameportion of said container in said opening portion;

(c) a window portion provided in said frame portion of said cover, fromwhich said locking pawl protrudes, said window portion being disposed soas to be located outward of an front end of said frame portion of saidcontainer in said opening portion, when said locking pawl is hitched tosaid hitched portion provided in said frame portion of said container insaid opening portion; and

(d) a vent hole provided in said frame portion of said container outwardof said front end of said frame portion of said container for connectingto said low cleanliness room.

According to the invention, the dust generated during the operation ofthe lock mechanism and flowed out of the window portion is carried tothe low cleanliness room by the air stream generated at the instancewhen the pawls are disengaged and the cover is released, thus preventingthe dust from flowing backward through the tip of the opening portion tothe inside of the container not to contaminate the inside of thecontainer.

The fourth embodiment of the invention is a container, wherein saidhitched portion comprises an engaged hole, and said engaged holefunctions as said vent hole.

According to the invention, numbers of the vent holes and engaged holesmay be reduced to facilitate the manufacture of the container.

The fifth embodiment of the invention is a container for receiving andtransporting a detesting dust article, which is mounted on a loaderdisposed in a border portion between a high cleanliness room and a lowcleanliness room, a cover of which is opened and closed by an openermechanism disposed in said loader in such manner that an opening portionof said container and said high cleanliness room is connected and shut,which includes:

(a) a lock mechanism disposed in said cover and operated by said openermechanism provided in said loader for locking and releasing said cover;

(b) a locking pawl in said lock mechanism for protruding from a frameportion of said cover and catching a hitched portion provided in a frameportion of said container in said opening portion;

(c) a window portion provided in said frame portion of said cover, fromwhich said locking pawl protrudes, said window portion being disposed soas to be located at a portion through which air stream flows directlytoward said low cleanliness room, said air stream being generated by apositive pressure applied to said high cleanliness room at an instancewhen said locking pawl is disengaged from said hitched portion torelease said cover.

According to the invention, the dust generated during the operation ofthe lock mechanism and flowed out of the window portion is directlycarried to the low cleanliness room by the air stream generated at theinstance when the pawls are disengaged and the cover is released, thuspreventing the contamination of the inside of the container.

The sixth embodiment of the invention is a container for receiving andtransporting a detesting dust article, which is mounted on a loaderdisposed in a border portion between a high cleanliness room and a lowcleanliness room, a cover of which is opened and closed by an openermechanism disposed in said loader in such manner that an opening portionof said container and said high cleanliness room is connected and shut,which includes:

(a) a taper-shaped guiding convex portion or a taper-shaped guidingconcave portion formed at a portion on an inner side of said cover withwhich said frame portion of said container in said opening portioncontacts;

(b) a taper-shaped guiding concave portion or a taper-shaped guidingconvex portion for being correspondingly fixed to said taper-shapedguiding convex portion or said taper-shaped guiding concave portionformed in said cover, formed at a portion on said frame portion of saidcontainer in said opening portion with which said inner side of saidcover contacts.

According to the invention, since the cover closes the opening portionwhile the taper-shaped guiding convex portion is fixed to the guidingconcave portion to determine the location, the cover is not erroneouslycontacted with the opening portion, thus preventing the dust from beinggenerated.

The seventh embodiment of the invention is a container for receiving andtransporting a detesting dust article, which is mounted on a loaderdisposed in a border portion between a high cleanliness room and a lowcleanliness room, a cover of which is opened and closed by an openermechanism disposed in said loader in such manner that an opening portionof said container and said high cleanliness room is connected and shut,which includes:

(a) an inner flange formed at an inner side of a frame portion of saidcontainer in said opening portion and an outer flange formed at an outerside of said frame portion of said container in said opening portion;

(b) said cover closing said opening portion by covering an inner side ofsaid outer flange;

(c) a ring-shaped concave portion formed at an inner side of said coverfor being fixed to said inner flange; and

(d) a gap formed between an inner surface of said inner flange and aninner wall at an inner side of said ring-shaped concave portion.

According to the invention, since the gap is formed between the innerperipheral surface of the inner flange and the inner wall at the innerperipheral side of the concave portion, it is possible to prevent two ofthem from contacting each other, thus preventing the dust from beinggenerated within the opening portion.

The eighth embodiment of the invention is a container, wherein akinematic coupling is disposed between said opener mechanism and saidcover, which cover is closed and opened by said opener mechanism, forpositioning of said opener mechanism and said cover.

According to the invention, since the determination of the location ofthe cover against the opener mechanism is carried out by the kinematiccoupling, the cover is prevented from erroneously contacting with theopening portion, thus preventing the generation of the dust.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(A) is a schematic oblique view illustrating a conventionalcontainer;

FIG. 1(B) is a B—B cross sectional view in FIG. 1(A) illustrating frameportions of the cover and the container, when the cover is closed;

FIG. 2 is a schematic oblique descriptive view observed from the lowcleanliness room, which illustrates the loader with the container of thefirst embodiment of the invention mounted thereon;

FIG. 3 is a vertical sectional view of the loader and the container inFIG. 2 which illustrates the loader and the container before the coveris released from the main body of the container;

FIG. 4 is a vertical sectional view of the loader and the container inFIG. 2 which illustrates the loader and the container in which the coveris released from the main body of the container of the invention and theopening portion of the container is connected to the high cleanlinessroom;

FIG. 5 is an oblique descriptive view illustrating an embodiment of thecontainer of the present invention in its entirety;

FIG. 6 is a schematic oblique descriptive view illustrating anembodiment of the container of the present invention shown in FIG. 5 inwhich parts of the container are disassembled;

FIG. 7(A) is a perspective view from the front, which illustrates thecover of the container of the invention;

FIG. 7(B) is a B—B cross-sectional view in FIG. 7(A);

FIG. 8 is a descriptive enlarged view illustrating an essential portionin FIG. 7(B);

FIG. 9(A) is a perspective view observed from the right side in FIG. 8;

FIG. 9(B) is a descriptive view illustrating the situation in which thelocking pawl in lock mechanism is disengaged from the hitched portion inFIG. 9(A):

FIG. 10(A) is a frontal descriptive view illustrating the frame portionof the container in the opening portion in FIG. 5;

FIG. 10(B) is a schematic oblique descriptive view of the guiding convexportion formed on the inner side of the cover so as to becorrespondingly fixed to the guiding concave portion in FIG. 10(A);

FIG. 11(A) is a schematic descriptive view illustrating the frameportion of the cover and the frame portion of the container in theopening portion shown in FIG. 8 together with the opening portion of thewall;

FIG. 11(B), (C), (D), (E) and (F) are schematic descriptive viewillustrating other embodiments corresponding to FIG. 11(A);

FIG. 12(G) and (H) are schematic descriptive view illustrating otherembodiments corresponding to FIG. 11(A).

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The best mode of the embodiments of the invention is described hereunderwith reference to FIGS. 2 to 11. The following embodiments do not limitthe scope of the invention. Skilled person in the field can thereforeexecute other embodiments within a scope of the invention according tothe present invention.

[Relationship between the container and the loader]

There is described the process for opening and closing the cover of thecontainer of the invention by the loader so as to connect and shut theopening portion of the container to the high cleanliness room.

As shown in FIG. 2, two loaders 1 and one control panel 3 are disposedon the wall 9 installed at the border portion between the highcleanliness room 5 and the low cleanliness room 7. One of the loader 1is assigned to the use only for carrying the silicon wafer into the highcleanliness room (i.e., loading), and the other loader 1 is assigned tothe use only for carrying the silicon wafer out of the high cleanlinessroom (i.e., unloading), for example, thus the silicon wafer is smoothlycarried into and out of the high cleanliness room along one circulatingroute.

Container 11 is mounted on the stage 13 of the loader 1, followed by thepositioning thereof. The positioning of the container and the stage iscarried out by the kinematic coupling provided on the stage and the baseportion 15 of the container (the member indicated by the numerous number17 in FIG. 2 is a male member which is a part of the kinematiccoupling).

The container may be mounted by man power, or the transporting robot orthe robot mounted on AGV running on the floor. Furthermore, the flange19 may be disposed on the upper portion of the container 11 in suchmanner that the container may be mounted by the transporting robotinstalled on the ceiling. The process defined in the standard can beapplied to mount the container.

In addition, the process defined in the standard can be applied to thepositioning of the container by means of the kinematic coupling

In FIG. 3, an opening portion 23 is formed on the wall 21 toward whichthe front of the container 11 mounted on the loader 1 faces. The openingportion 23 is covered by the door 25 called as a closure. The gapbetween the door and the opening portion 23 is not necessarily perfectlysealed, and a specific space 27 is formed and opened. By the positivepressure applied to the high cleanliness room 5, the air stream 29 isgenerated from the high cleanliness room to the low cleanliness room 7through the specific space 27, thus the dust can be prevented fromflowing into the high cleanliness room by the air stream 29.

Firstly, the stage 13 on which the container 11 is mounted is caused toapproach the door 25 by a driving mechanism 31. The door 25 alsofunctions as the opener 37 which is a part of the opener mechanism 35for opening and closing the cover 33 of the container 11.

More specifically, the kinematic coupling is disposed on the side of theopener 37 facing toward the cover 33 of the container 11 in the lowcleanliness room 7, to carry out the positioning (the member indicatedby numerous number 39 in FIG. 3 is a male member which is a part of thekinematic coupling). In addition, the cover 33 is fixed to the opener 37by fixing means (not shown). Furthermore, the key 41 disposed in theopener 37 is inserted to the key hole disposed in the cover while thecover is fixed to the opener by the above-mentioned fixing means, andthen the key 41 is turned so as to cause the lock mechanism disposedinside of the cover to operate. As a result, the locking pawls in thelock mechanism in the cover are released from the hitched portionprovided in the frame portion of the container 11 in the openingportion.

Then, the stage on which the container 11 is mounted moves backward alittle, while the cover 33 is fixed to the opener 37. By this backwardmovement of the stage, the cover 33 is released from the container 11 sothat the container 11 is opened at the opening portion thereof.

Then, the opener 37 with the cover 33 fixed thereto is lowered into theloader 1 by the driving mechanism 43 provided in the opener mechanism35. Then, the stage on which the container 11 is mounted moves forwardagain. By this forward movement of the stage, the opening portion of thecontainer 11 is connected to the high cleanliness room through theopening portion 23 of the wall 21 (refer to FIG. 4). At this moment, theprescribed space 45 is formed between the frame portion of the container11 in the opening portion and the opening portion 23 of the wall,through which the air stream 47 is generated from the high cleanlinessroom 5 to the low cleanliness room 7, thus the dust in the lowcleanliness room is prevented from flowing into the high cleanlinessroom 5.

The silicon wafer as the detesting dust article is loaded into the highcleanliness room 5 from the inside of the container 11, and workedtherein. After worked, the silicon wafer may be unloaded out of the highcleanliness room 5 to the container 11 which is mounted on anotherloader 1, or to the container 11 which is mounted on the same loader 1.The above-mentioned loading and unloading of the silicon wafer iscarried out by the known means such as a scalar type robot for cleanroom installed in the high cleanliness room 5.

When the silicon wafer is moved out of the high cleanliness room to thecontainer 11, the reverse processes of the loading of the silicon waferinto the high cleanliness room are carried out. More specifically, thestage 13 on which the container 11 is mounted moves backward. Then, theopener 37 with the cover 33 fixed thereto is raised by the drivingmechanism 43 of the opener mechanism 35 to return to the initialposition. Then, the stage 13 moves forward a little again so that thecover 33 of the container covers the opening portion of the container11. Then, the key 41 of the opener 37 is turned in reverse to cause thelocking pawls in the lock mechanism to engage the hitched portion, thuslocking and sealing the opening portion of the container 11 by the cover33. Then, after the fixing means of the opener 37 releases the cover,the stage 13 is moved backward again, thus the container 11 is ready tobe carried in the low cleanliness room 7.

[Construction of the container]

Examples of the best mode of the container of the invention is describedhereunder with reference to FIGS. 5 to 11.

(General description) As shown in FIG. 5, the container 11 of thisembodiment comprises a schematic box type container, in the frontportion of which the square frame portion is formed in the openingportion. The inside of the container 11 is used for the space to receivethe silicon wafer 51 as the detesting dust article. On the three innerwalls of the container, i.e., the right and left sides, and the backside, the parts called as the teeth 53 and the stopper 54 (refer to FIG.6) are furnished to horizontally hold a plurality of silicon wafers,each of which is parallel each other. On the upper surface of theoutside of the container, the flange 19 is fixed by a plurality ofscrews 55 in such manner that the flange is parallel to the uppersurface of the container with a prescribed distance apart therefrom. Theflange 19 is held by the transporting robot in the ceiling. The baseportion 15 is fixed on the bottom outer surface of the container. Thekinematic coupling for carrying out the positioning of the containertogether with the stage 13 of the loader 1 (refer to FIG. 2) isfurnished on the base portion 15. More specifically, there is furnishedon the base portion 15, the female member 57 having a V-shaped groove(refer to FIG. 6) to receive a rod-shaped protrusion as the male member17 which is a part of the kinematic coupling (refer to FIG. 2). Threepairs of the above-mentioned female member 57 and the male member 17 areprovided in such manner that three lines formed by the bottom tips ofthe V-shaped grooves are extended so as to cross at the single point inthe center portion of the base portion 15. By this arrangement of thekinematic coupling, the positioning of the container is correctlycarried out.

The cover 33 for opening and closing the opening portion 49 of thecontainer comprises a double structure of the outer cover 59 and theinner base 61 (refer to FIG. 6). The holder 63 for holding the siliconwafers at the front side of the container is further furnished at theinner side of the base 61 (refer to FIG. 6), to hold and fix theplurality of silicon wafers which are placed in parallel each other soas not to move or slide during the transportation thereof

(Lock mechanism)

As shown in FIGS. 7 and 8, the lock mechanism 65 is disposed in thespace between the outer cover 59 and the base 61 of the cover 33. Thelock mechanism is described more specifically with reference to the lockmechanism 65 in the right side in FIG. 7. The cam 69 with the key holeformed is disposed so as to turn around the key hole. The key hole ofthe cam 69 is formed to be correspondingly connected to the key hole 67(refer to FIG. 5) provided in the outer cover 59 in the cover 33. Nextto the cam 69, there is provided a slider 71 which can be slidvertically, i.e., up and down, by the cam 69. At each of the upper andlower ends of the long slider 71, there is formed a cylindricalprotrusion 73. The cylindrical protrusion 73 is engaged in the U-shapedcut portion 77 which is formed at the rear end of the locking pawl 75.The locking pawl 75 protrudes from the window portion 81 formed in theframe portion of the base 61 which is a part of the cover 33, so as toenable to turn around the turning axis 79. The locking pawl protrudesbackward from the front side of the cover in such manner that thelocking pawl is inserted to the engaged hole 83 which is the hitchedportion provided in the frame portion of the container 11 in the openingportion 49.

The lock mechanism 65 in the left side in FIG. 7 includes an idle gear85 in contrast with the lock mechanism 65 in the right side in FIG. 7.This arrangement is made to cause two keys 47 to turn in the samedirection, each of which keys is inserted to respective key hole 67 andturned. The key hole 67 is formed in the idle gear 85 so that the rightand left sliders 71 can be synchronously sled in vertical direction bymeans of the cam 69 which includes gear 87 engaging the idle gear 85 inthe same axis thereof.

(Cover and the frame portion of the opening portion)

The cover 33 and the frame portion of the container in the openingportion 49 are described in detail with reference to FIG. 8. In theframe portion of the container in the opening portion 49, there isdisposed a base portion 89 which extends outwardly the frame portion. Atthe inner side of the base portion 89, there is formed an inner flange91, and at the outer side of the base portion 89, there is formed anouter flange 93. The cross-sectional view of the above inner and outerflanges and the base portion makes the reverse U-shape. At the rearportion of the reverse U-shape, i.e., the base portion 89, the engagedhole 83 as the hitched portion is formed. The protrusion 95 is formedoutwardly at the lowest end of the engaged hole 83. The peak of theprotrusion 95 makes a moderate curved surface. The locking pawl 75 isengaged with the above curved surface of the protrusion 95 so as tofirmly seal the cover 33 (refer to FIG. 9). Four engaged holes 83 aredisposed correspondingly to four locking pawls 75.

In the frame portion of the base 61 which is a part of the cover 33,there is provided a concave portion 97 which houses therein the innerflange 91 of the frame portion of the container 11 in the openingportion 49. Furthermore, the frame portion of the base 61 of the cover33 has such a shape in the cross section that the frame portion isapproximately housed by the reverse U-shape portion comprising the innerflange 91, the base portion 89 and the outer flange 93 of the frameportion of the container 11 in the opening portion 49. It is designedthat a prescribed gap 99 is formed between the inner surface of theinner flange 91 (i.e., inner side of the container) and the inner wallat the inner side of the ring-shaped concave portion 97, when the frameportion of the cover is housed by the reverse U-shaped portion of theframe portion of the container in the opening portion.

As shown in FIG. 10, in the right and left frame portions of the openingportion 49, there are formed guiding concave portions 121 at theintermediate location between the upper and lower engaging holes 83. Inthe inner frame portion of the cover 33, there are formed guiding convexportions 123 so as to be engaged with the above-mentioned guidingconcave portion 121. The guiding concave portion 123 has a tapered shapewhich makes smaller toward the depth thereof, while the guiding convexportion 121 has a tapered shape which makes smaller toward the tipthereof, correspondingly.

(Positioning of the cover and the opener)

There is provided the kinematic coupling to carry out the positioningbetween the cover 33 and the opener 37 (refer to FIG. 3). Morespecifically, there are formed three V-shaped grooves 125 (refer to FIG.5) as the female member on the outer cover 59 of the cover 33, whichcorrespond to the three rod type protrusions as the male member 39formed in the opener 37 which is a part of the kinematic coupling. Sincethe kinematic coupling functions as approximately same as the kinematiccoupling provided in the base portion 15, the detail description thereofis found in the above-mentioned base portion.

(Scale of the gap between the opening portion of the wall and thecontainer)

As shown in FIG. 11(A) which schematically represents the relationshipbetween the frame portions of the cover and the frame portion of thecontainer in the opening portion shown in FIG. 8 together with theopening portion 23 of the wall, the scale of the gap 45 between theopening portion 23 of the wall 21 and the container, namely, the gap 45between the outer surface of the outer flange 93 and the inner surfaceof the opening portion 23 of the wall 21 is within a range of 4 to 6 mm,preferably 5 mm. The length 127 thereof along the air stream 47 iswithin a range of 10 to 20 mm, preferably 15 mm. According to theconventional apparatus, the above-mentioned length along the air streamis too short so that a turbulent flow is generated in the air streamafter passing the gap 45, thus drawing the dust in the low cleanlinessroom 7 and causing the dust to flow into the high cleanliness room 5.Contrary to the conventional apparatus, in the present invention, thelength of the gap 45 is long enough so that the air stream makes alaminar flow, and the turbulent flow in the air stream is effectivelyprevented from being generated, thus the dust is prevented from flowinginto the high cleanliness room 5.

The cleanliness in the high cleanliness room 5 is 5 Class1, while thecleanliness in the low cleanliness room is 7 Class1. The pressure in thehigh cleanliness room 5 is higher than that in the low cleanliness room7 by for example 35 Pa.

[Function and effect]

From the above embodiment, the following functions and effects can beobtained.

When the cover 33 is to be opened by means of the opener mechanism 35,the key 41 of the opener 37 is inserted into the key hole 67 of thecover 33 and turned 90 degrees in clockwise in FIG. 7(A). Then, twosliders 71 are synchronously sled downward by means of the operation ofthe cam 69 and the idle gear 85 to cause the locking pawl 75 to turn incounterclockwise, thus releasing the engagement with the engaged hole 83as shown in FIG. 9(B). At the instant when the cover 33 is opened, theair stream 47, 48 (refer to FIG. 11(A)) is generated by the positivepressure applied to the high cleanliness room 5. At the same time, thedust is generated by the operation of the above-mentioned lockmechanism, i.e., the friction between the cam 69, the idle gear 85, theslider 71, and the locking pawl 75. Thus generated dust can beeffectively prevented from flowing into the container and fromcontaminating therein. The reason thereof is described hereunder. Morespecifically,

(1) Since the space formed by the reverse U-shaped portion comprisingthe inner flange 91, the base portion 89, and the outer flange 93 isclosed in the rear (namely, the direction toward the rear portion of thecontainer), the air stream 48 is hardly generated inside of the space.Accordingly, the dust generated and flown out of the window portion 81of the locking pawl 75 which is located in the back side of the space ishardly carried by the air stream 48. More specifically, the dust can beeffectively prevented from being carried by the air stream 48 around thefront end of the frame portion of the container in the opening portion49, i.e., the tip of the inner flange 91, into the inside of thecontainer 11.

In other words, since the window portion 81 for the locking pawl 75 islocated outward of the front end of the frame portion of the containerin the opening portion 49, i.e., the tip of the inner flange 91, andbackward thereof, the air stream is prevented from flowing in reverse.

(2) Furthermore, the generated air stream 48 passes the space betweenthe outer flange 93 and the frame portion of the cover 33, and thenflows directly into the low cleanliness room 7 through the engaged hole83 which also functions as the vent hole. Accordingly, the air stream 48is further effectively prevented from flowing in reverse around the tipof the inner flange 49.

In addition, since the engaged hole 83 additionally functions as thevent hole, the manufacture of the container 11 becomes easier incomparison with the case in which the engaged hole and the vent hole areprovided separately.

In the above, the reason for preventing the dust from contaminating thecontainer 11 is described in the case that the dust is generated by thefriction in the lock mechanism. However, the dust is generated by othercauses. Particularly, the friction between the cover 33 and the frameportion of the container in the opening portion 49 is another cause togenerate the dust in addition to the lock mechanism 35. The reason forpreventing the dust generated by the friction between the cover 33 andthe frame portion of the container in the opening portion 49 fromcontaminating the inside of the container according to the presentinvention is described hereunder.

(1) Since the tapered guiding convex portion 123 is engaged with thetapered guiding concave portion 121, both of which have enough length ofthe protrusion or recession (refer to FIG. 10), the positioning of thecover 33 and the frame portion of the container in the opening portion49 is effectively carried out, and then the cover 33 contacts the frameportion of the container in the opening portion 49, when the cover 33 isto be closed, thus preventing the dust from being generated. Whereas inthe conventional apparatus, the cover contacts the frame portion of thecontainer in the opening portion to generate the dust, because thepositioning of the cover and the frame portion of the container in theopening portion is not sufficient.

(2) Since the gap 99 is formed between the inner surface of the innerflange 91 and the inner surface of the inner wall of the concave portion97 as shown in FIG. 8, the friction between both of them can beprevented from being produced, thus preventing the dust from beinggenerated in frame portions of the cover and the container 11 in theopening portion 49. Even if the outer surface of the inner flange 91contacts the inner surface of the outer wall of the concave portion 97because of the insufficient positioning of the frame portion of thecontainer in the opening portion 49 and the cover 33, the friction bythe above-mentioned contact occurs outward of the front end of the frameportion of the container in the opening portion 49, i.e., the tip of theinner flange 91, the dust generated by the friction can be preventedfrom flowing around the tip of the inner flange 91 into the inside ofthe container 11. Furthermore, with a wider gap 99, the dust isprevented from being generated in the frame portions of the cover andthe container in the opening portion 49 even if the positioning of theframe portion of the container in the opening portion and the cover 33is insufficient.

(3) In order to carry out the correct positioning of the frame portionof the container in the opening portion 49 of the cover 33, it isnecessary that the opener mechanism 35 operates correctly, and that thesufficient positioning of the cover 33 and the opener mechanism 35 hasto be carried out. The above-mentioned sufficient positioning can beattained by the use of the kinematic coupling between the opener 37 inthe opener mechanism 35 and the cover 33. Thus, the dust can beprevented from being generated by the unnecessary friction between thecover 33 and the frame portion of the container in the opening portion49.

Furthermore, according to the present invention, since the locking pawl75 protrudes backward of the container and is engaged with the hitchedportion as if the hitched portion is drawn toward the cover, thepressure power applied to the frame portion of the container in theopening portion 49 by the cover 33 increases, thus enabling a firmsealing of the container.

[Other embodiment]

The cross-sectional view of the frame portion of the container in theopening portion 49 and the frame portion of the cover 33 has beendescribed with reference to FIG. 8 in the above embodiment. However, inthe present invention, other structures thereof are available as shownin FIGS. 11 and 12. More specifically, when the cover and the frameportion of the container shown in FIG. 8 are illustrated together withthe opening portion of the wall, the descriptive view of the abovebecomes the view as shown in FIG. 11(A). In addition, the engaged hole83 additionally functions the vent hole in the above embodiment.However, in the present invention, it is possible to provide the hitchedportion 133 and the vent hole 131 separately as shown in FIG. 11(B). Inthis case, the locking pawl may protrudes not backward but outward,i.e., in the radius direction of the frame portion of the container inthe opening portion 49. The air stream 48 directly flows through thevent hole 131 into the low cleanliness room 7.

Furthermore, as shown in FIG. 11(C), the locking pawl may protrudesoutward of the frame portion of the container in the opening portion 49,and the engaged hole 83 with which the locking pawl is engagedadditionally functions as the vent hole.

As shown in FIG. 11(D), the hitched portion 133 may not pierce throughthe base portion 89 of the frame portion of the container in the openingportion 49. In this case, a part of the back portion of the hitchedportion 133 may be pierced through and caused to function as the venthole.

Furthermore, the frame portion of the container in the opening portion49 has the inner flange 91, the base portion 89 and the outer flange 93.However, in the present invention, as shown in FIGS. 11(E) and (F), forexample, the frame portion of the the container in the opening portion49 may have the inner flange 91 and the base portion 89 without theouter flange 93. Without the outer flange 91, FIG. 11(E) is the same asFIG. 11(A), and FIG. 11(F) is the same as FIG. 11(D).

In addition, in the present invention, as shown in FIGS. 11(G) and (H),for example, the frame portion of the container in the opening portion49 may have the base portion 89 and the outer flange 93 without theinner flange 93. In this case, the vent hole 131 is preferably formed inthe base portion 89 near the hitched portion 133 so that the air streamcarrying the dust, which flows out of the window portion 81 (refer toFIG. 8) for the locking pawl 75, directly flows into the low cleanlinessroom 7 (refer to FIG. 11(G)). In addition, a part of the back portion ofthe hitched portion 133 may be pierced through and caused to function asthe vent hole, thus flowing the air stream 48 directly into the lowcleanliness room 7.

Furthermore, in connection with the guiding convex portion 123 and theguiding concave portion 121 to carry out the positioning of the cover 33and the frame portion of the container in the opening portion 49, theguiding convex portion 123 is formed on the cover and the guidingconcave portion 121 is formed on the frame portion of the container inthe opening portion 49 in the above embodiment. However, therelationship thereof may be in reverse in the present invention.

Two pairs of the guiding concave portion 121 and the guiding convexportion 123 are formed in the above embodiment. However, three or fourpairs thereof may be formed in the present invention.

In addition, the kinematic coupling is used for the positioning of thecover 33 and the opener mechanism 35 in the above embodiment. However,other means of the positioning may be employed in the present invention.

The opener mechanism 35 is provided in the low cleanliness room alongthe border between the high cleanliness room 5 and the low cleanlinessroom 7 in the above embodiment. However, the opener mechanism may beprovided in the high cleanliness room 8. Since the dust generated in thelock mechanism 65 flows out of the window portion 81 for the lockingpawl 75 at the instant when the lock mechanism is unlocked, i.e., thelocking pawl 75 is disengaged with the hitched portion to release thecover 33, the contamination of the container is expected to be preventedby means for treating the dust in that instant not to contaminate theinside of the container 11.

In order to open and close the cover 33, the opener 37 moves upward anddownward, and the stage on which the container 11 is mounted movesforward and backward in the above embodiment. However, the stage 13 onwhich the container 11 is mounted may not move forward and backward,while the opener 37 moves forward and backward as well as moves upwardand downward by the opener mechanism. More specifically, after the stageon which the container is mounted is positioned in a prescribedlocation, the opener 37 is raised and caused to approach (or retreat)the container 11, and then, after releasing the lock mechanism, theopener 37 is retreated from the container (or moved forward) andlowered.

The stage 13 is moved forward and backward by the driving mechanism 31in the above embodiment. However, the driving mechanism may not beprovided in the present invention. For example, bearings, wheels orrollers may be furnished and the stage 13 may be moved forward andbackward by human power or robots.

As described above, according to the present invention, it is possibleto prevent the inside of the container in which the detesting dustarticle such as the silicon wafer is received and transported from beingcontaminated by the dust generated when the cover of the container isopened and closed.

The detesting dust article received and transported by the container ofthe present invention may be the semiconductor substrate such as theliquid crystal substrate, and the article in the medical field, andtherefore is not limited to the silicon wafer.

What is claimed is:
 1. A container for receiving and transporting adetesting dust article, which is mounted on a loader disposed in aborder portion between a high cleanliness room and a low cleanlinessroom, a cover of which is opened and closed by an opener mechanismdisposed in said loader in such manner that an opening portion of saidcontainer and said high cleanliness room is connected and shut, whichincludes: (a) a lock mechanism disposed in said cover and operated bysaid opener mechanism provided in said loader for locking and releasingsaid cover; (b) a locking pawl in said lock mechanism for protrudingfrom a frame portion of said cover and catching a hitched portionprovided in a frame portion of said container in said opening portion;and (c) a window portion provided in said frame portion of said cover,from which said locking pawl protrudes, said window portion beingdisposed so as to be located outward and backward of a front end of saidframe portion of said container in said opening portion, when saidlocking pawl is hitched to said hitched portion provided in said frameportion of said container in said opening portion.
 2. A container asclaimed in claim 1, wherein said frame portion of said container in saidopening portion comprises said hitched portion which is located betweensaid inner flange and said outer flange, said window portion for saidlocking pawl is located in said hitched portion when said locking pawlis hitched to said hitched portion, and said frame portion of saidcontainer comprises a tip of said inner flange.
 3. A container forreceiving and transporting a detesting dust article as claimed in claim1, which further comprises: (a) a taper-shaped guiding convex portion ora taper-shaped guiding concave portion formed at a portion on an innerside of said cover with which said frame portion of said container insaid opening portion contacts; (b) a taper-shaped guiding concaveportion or a taper-shaped guiding convex portion for beingcorrespondingly fixed to said taper-shaped guiding convex portion orsaid taper-shaped guiding concave portion formed in said cover, formedat a portion on said frame portion of said container in said openingportion with which said inner side of said cover contacts.
 4. Acontainer for receiving and transporting a detesting dust article asclaimed in claim 1, which further comprises: (a) said frame portionhaving an inner flange formed at an inner side of said frame portion andan outer flange formed at an outer side of said frame portion of saidcontainer in said opening portion; (b) said cover closing said openingportion by covering an inner side of said outer flange; (c) aring-shaped concave portion formed at an inner side of said cover forbeing fixed to said inner flange; and (d) a gap formed between an innersurface of said inner flange and an inner wall at an inner side of saidring-shaped concave portion.
 5. A container as claimed in claim 1,wherein a kinematic coupling is disposed between said opener mechanismand said cover, which cover is closed and opened by said openermechanism, for positioning of said opener mechanism and said cover.
 6. Acontainer for receiving and transporting a detesting dust article, whichis mounted on a loader disposed in a border portion between a highcleanliness room and a low cleanliness room, a cover of which is openedand closed by an opener mechanism disposed in said loader in such mannerthat an opening portion of said container and said high cleanliness roomis connected and shut, which includes: (a) a lock mechanism disposed insaid cover and operated by said opener mechanism provided in said loaderfor locking and releasing said cover; (b) a locking pawl in said lockmechanism for protruding from a frame portion of said cover and catchinga hitched portion provided in a frame portion of said container in saidopening portion; (c) a window portion provided in said frame portion ofsaid cover, from which said locking pawl protrudes, said window portionbeing disposed so as to be located outward of a front end of said frameportion of said container in said opening portion, when said lockingpawl is hitched to said hitched portion provided in said frame portionof said container in said opening portion; and (d) a vent hole providedin said frame portion of said container outward of said front end ofsaid frame portion of said container for connecting to said lowcleanliness room.
 7. A container as claimed in claim 6, wherein saidhitched portion comprises an engaged hole, and said engaged holefunctions as said vent hole.
 8. A container as claimed in claim 6,wherein said vent hole functions as a ventilating hole and said hitchedportion.
 9. A container for receiving and transporting a detesting dustarticle, which is mounted on a loader disposed in a border portionbetween a high cleanliness room and a low cleanliness room, a cover ofwhich is opened and closed by an opener mechanism disposed in saidloader in such manner that an opening portion of said container and saidhigh cleanliness room is connected and shut, which includes: (a) a lockmechanism disposed in said cover and operated by said opener mechanismprovided in said loader for locking and releasing said cover; (b) alocking pawl in said lock mechanism for protruding from a frame portionof said cover and catching a hitched portion provided in a frame portionof said container in said opening portion; (c) a window portion providedin said frame portion of said cover, from which said locking pawlprotrudes, said window portion being disposed so as to be located at aportion through which air stream flows directly toward said lowcleanliness room, said air stream being generated by a positive pressureapplied to said high cleanliness room at an instance when said lockingpawl is disengaged from said hitched portion to release said cover.